The Obama administration used that explanation for more than a week after assailants killed the U.S. ambassador to Libya and three other Americans. Most notably, the U.S. ambassador to the United Nations, Susan Rice, said in several TV interviews five days after the attack that it appeared to be "spontaneous" violence spinning out of protests of the film.

State Department spokeswoman Victoria Nuland backed up Rice's statements in a press briefing a day later: "I would simply say that ... the comments that Ambassador Rice made accurately reflect our government's initial assessment."

The House Oversight Committee will hold a hearing about the disaster in Libya today on Capitol Hill.